The exemplary embodiment relates to lubricant additives and in particular to succinimide derivatives of hydroxyaromatic compounds that are useful in lubricating compositions.
Thermal and mechanical stresses on lubricants, such as engine and driveline oils, tend to increase formation of deposits on the lubricated components, such as internal combustion engines and driveline components. This can negatively impact the performance of the lubricated components through reduction in engine efficiency or overall life-expectancy. Such lubricants generally incorporate, in addition to a base oil, a number of additives, including friction modifiers, antiwear agents, antioxidants, dispersants, and detergents, that are used to protect lubricated components from wear, oxidation, soot deposits, corrosion, acid build up, and the like, and to improve water tolerance and compatibility of formulation components.
Branched para-C12-alkylphenols, including p-dodecylphenol (PDDP), formed from tetrapropene, have seen extensive commercial use as chemical intermediates in the production of oil and lubricant additives for gasoline and diesel-powered engines. Recently, however, some countries have placed limits on the amount PDDP which is considered acceptable. Therefore it is desirable to develop an alternative to PDDP and other alkylphenols for use as detergents.
There have been several efforts to prepare detergents that do not contain Cn alkyl phenols derived from oligomers of propylene. These include U.S. Pub Nos. 2008/0269351, 2011/0118160, 2011/0124539, 2011/0190185, and WO 2013/059173. Several dispersant/detergent compounds are based on the reaction of an alkenylsuccinic acid or anhydride with an amine or polyamine to produce an alkylsuccinimide or an alkenylsuccinamic acid as determined by selected conditions of reaction. Polyisobutylene succinimide dispersants are described in U.S. Pat. No. 6,770,605. Other compounds are disclosed in U.S. Pat. Nos. 3,816,353, 3,864,286, 4,058,472, 4,221,673, 4,643,838, 4,729,848, 5,510,043, 6,235,688 and 6,310,009, and U.S. Pub. Nos. US 2007/0049508, 2005/0288194, 2004/077507, 2014/130767, WO 2014193543, and EP 2374866 A1.